/Engine/Source/Developer/Datasmith/DatasmithExporter/Public/DatasmithExportOptions.h
Creation of automatic flatten projection of UVs to be used on lightmaps
static [EDSExportLightmapUV](API\Developer\DatasmithExporter\EDSExportLightmapUV) LightmapUV = EDSExportLightmapUV::Always;